Network directed cell broadcasts for emergency alert system

ABSTRACT

Systems and methods for providing alerts to end users of networked enabled portable devices are provided so that the end users are made aware when broadcast emergency alerts are issued. The systems and methods provide a way for a portable device to receive information about an emergency alert broadcast of which the user should be aware, e.g., from the EAS, and to notify the user of the emergency alert. A flag provides an indication the EAS should be on and the systems and method override the settings made by a user to a portable device to enable EAS reception. The user may then be automatically taken to the emergency alert information by having the portable device automatically tune to the emergency broadcast information, or the user may optionally retrieve the emergency information by tuning to the emergency broadcast channel, or the user may otherwise be presented with a reference to the emergency data (e.g., a link to the information).

CROSS REFERENCE TO RELATED APPLICATIONS

The instant application is a continuation of, and claims priority to,U.S. patent application Ser. No. 13/904,145, filed May 29, 2013. U.S.patent application Ser. No. 13/904,145 is a continuation of, and claimspriority to, U.S. patent application Ser. No. 13/689,279, filed Nov. 29,2012. U.S. patent application Ser. No. 13/689,279, issued Jul. 9, 2013,with U.S. Pat. No. 8,482,404. U.S. patent application Ser. No.13/689,279 is a continuation of, and claims priority to, U.S. patentapplication Ser. No. 11/498,572, filed Aug. 2, 2006. U.S. patentapplication Ser. No. 11/498,572 issued Feb. 5, 2013 with U.S. Pat. No.8,368,530. U.S. patent application number Ser. No. 13/904,145 isincorporated by reference herein in their entirety. U.S. patentapplication number Ser. No. 13/689,279 is incorporated by referenceherein in their entirety. U.S. patent application number Ser. No.11/498,572 is incorporated by reference herein in their entirety. U.S.Pat. No. 8,482,404 is incorporated by reference herein in theirentirety. U.S. Pat. No. 8,368,530 is incorporated by reference herein intheir entirety.

FIELD OF THE INVENTION

The present invention is directed to a notification framework andmethods for reporting emergency alerts, such as those issued by theEmergency Alert System (“EAS”).

BACKGROUND

Some existing broadcast technologies, such as Cell Broadcast, MultimediaBroadcast/Multicast Service (“MBMS”), and video broadcast, e.g., DigitalVideo broadcast-Handheld (“DVB-H”), MediaFLO, have been proposed tosupport emergency alert notification(s) to wireless subscribers. Aproblem with such broadcast technologies, however, is that the end userdoes not know when an emergency alert is broadcast, and thus does notknow that they need to tune to an appropriate broadcast channel for theemergency alert information.

While it has been proposed to continuously monitor the wirelesssubscriber's handset to determine if an emergency alert is beingbroadcast, continuous monitoring by the wireless subscriber's handset ofthe various broadcast technologies to determine if an emergency alert isbeing issued will likely have a major impact on the handset battery lifedepending upon which broadcast technology/technologies are beingcontinuously monitored (e.g., Cell Broadcast). With current battery lifelimits, the end user experience would be impacted due to reduced handsetbattery life.

Accordingly, improved ways of notifying users of EAS alerts vianetworked portable devices supporting telephony radio network and/orbroadcast technologies are desired. Moreover, ways of notifying users ofalerts are desired that do not require ongoing polling of an emergencycommunication channel.

SUMMARY OF THE INVENTION

The invention provides systems and methods for providing alerts to endusers of networked enabled portable devices so that the end users aremade aware when emergency alerts are issued. Some portable devices maybe capable of receiving EAS broadcasts, but may optionally disable thefeature. The various preferred embodiments describe a way for a portabledevice to receive information about an emergency alert of which the usershould be aware, e.g., from the EAS, and to notify the user of theportable device of the emergency alert without requiring action of theuser even when the EAS broadcast reception has been disabled. A systemand method enable the EAS broadcast reception on the portable devicesuch that it can then automatically tune to the emergency broadcastinformation, or the user may otherwise be presented with a reference tothe emergency data (e.g., a link to the information).

Other features of the invention are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The systems and methods for alerting in accordance with the inventionare further described with reference to the accompanying drawings inwhich:

FIG. 1 illustrates an exemplary, non-limiting reporting framework forinforming users of portable devices of emergency broadcast alerts inaccordance with the invention;

FIG. 2 is a flow diagram of an exemplary implementation of a processwhereby a user's device becomes aware of an emergency alert inaccordance with the invention;

FIG. 3 is an exemplary, non-limiting flow diagram of a process fordelivering emergency information via broadcast networks supported by abroadcast processor of the user device;

FIG. 4A illustrates an overview of a network environment suitable forservice by embodiments of the invention;

FIG. 4B illustrates a GPRS network architecture that may incorporatevarious aspects of the invention; and

FIG. 4C illustrates an alternate block diagram of an exemplaryGSM/GPRS/IP multimedia network architecture in which the invention maybe employed.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Overview

As described in the background, with current implementations ofbroadcast technologies, there are no indications to end users that anemergency alert is being broadcast using broadcast technologies.Therefore, subscribers or users of portable devices having broadcastcapabilities, such as cell phones or the like, do not know when anemergency alert may be broadcast over any of the broadcast technologies.Moreover, any attempt to continuously monitor for emergency alerts mayhave unnecessary negative impact on battery life.

Accordingly, the system and methods described herein simultaneouslyaddresses both problems since (1) user device battery life does notbecome drained because the systems and methods described avoidcontinuous monitoring of broadcast technologies and (2) the user can benotified in real-time via an emergency alert mechanism of the inventionwhich is implemented on the user device, and supported by one or moretelephony radio networks.

Thus, in various embodiments, the system and methods described provide away for a portable device to receive information about an emergencyalert of which the user should be aware, e.g., from the EAS, and tonotify the user of the portable device of the emergency alert withoutrequiring action of the user. The user may then automatically view theemergency alert information, optionally retrieve the emergencyinformation by tuning to the emergency broadcast channel, or bepresented with a reference to the emergency data (e.g., a link to theinformation) so that a user can otherwise view the emergencyinformation.

Systems and Methods for Providing EAS Alert Notification

To avoid the continuous monitoring of a broadcast channel for emergencyalert information, a portable device in accordance may receiveinformation about an emergency alert of which the user should be aware,e.g., from the EAS, in order to notify the user of the emergency alertwithout requiring action from the user to find out about the presence ofthe emergency alert.

An emergency alert indicator bit on control channel(s) of a telephonynetwork with which the device communicates can be monitored. When theuser device detects the setting of the emergency alert indicator bit onthe control channel(s) that it is already monitoring, the device is ableto immediately lead the user to the emergency information, or instructthe end user with pre-provisioned information about the emergency alert,and any associated broadcast channels that contain the emergency alert.In this fashion, the user device does not have to continuously monitorthe broadcast channels for any possible emergency alerts.

The user may be notified via any one or more of visual feedback by theportable device (e.g., a display of the portable device, backlighting,LEDs, etc.), auditory feedback (e.g., an alarm sound) or mechanicalfeedback (e.g., vibration of the phone). In addition, whether displayedautomatically or at the option of the user, the emergency alertinformation may be rendered by the portable device via a display (e.g.,symbols, pictures, text, etc.) and/or an audio speaker (e.g.,pre-recorded EAS voice message, text-to-speech signal, etc.) and/or anyother known form of human communication (e.g., Morse code).

As shown in more detail in the block diagram of FIG. 1, a portabledevice 20 is shown for receiving notifications of emergency alertinformation. In FIG. 1, for the avoidance of doubt, portable or mobiledevices 20 may include a variety of computing devices including (a)portable media players, e.g., portable music players, such as MP3players, walkmans, etc., (b) portable computing devices, such aslaptops, personal digital assistants (“PDAs”), cell phones, portableemail devices, thin clients, portable gaming devices, etc., (c) consumerelectronic devices, such as TVs, DVD players, set top boxes, monitors,displays, etc., (d) public computing devices, such as kiosks, in-storemusic sampling devices, automated teller machines (ATMs), cashregisters, etc., (e) navigation devices whether portable or installedin-vehicle and/or (f) non-conventional computing devices, such askitchen appliances, motor vehicle controls (e.g., steering wheels), etc.Moreover, while some embodiments are directed to systems and method foruse in portable devices, as one of ordinary skill in the art canappreciate, the techniques of the invention are by no means limited topractice on portable devices, but may also apply to standalone computingdevices, such as personal computers (“PCs”), server computers, gamingplatforms (e.g., Xbox), mainframes, etc.

Returning to FIG. 1, in one embodiment of the invention, storage 22 onthe user device 20 is populated with emergency broadcast informationfrom a network-based emergency broadcast information database 10. As oneof ordinary skill in the art can appreciate, this information can beprovided and updated via over the air programming methodologies.Emergency broadcast information may, for instance, include the followingtypes of information: (A) information about available broadcasttechnologies (e.g., Cell Broadcast, MBMS, DVB-H, MediaFLO, etc.), (B)information concerning which broadcast technologies or network(s), suchas broadcast network 60, are specifically supported by the device 20 and(C) information about emergency broadcast channels associated with eachavailable broadcast technology.

FIG. 1 is further described with reference to the exemplary,non-limiting flow diagrams of FIGS. 2 and 3. FIGS. 2 and 3 providedescription of exemplary implementation of the various methods andsystems of the receiving EAS broadcasts. FIG. 2 is a flow diagram of anexemplary implementation of a process whereby a user's device becomesaware of an emergency alert. At 500, an emergency alert network 50notifies the emergency alert interface server/services 40, which iscommunicatively coupled to network 30, such as a carrier network, thatan emergency alert message is being broadcast. At 510, the emergencyalert interface server 40 notifies the telephony radio network 30 thatan emergency alert is being broadcast using broadcast technologies. At520, the telephony radio network 30 informs the telephony processor 24of portable device 20 that an emergency alert message is beingbroadcast, e.g., using a pre-defined, standardized indicator bit on atleast one telephony network control channel, an SMS message, a datachannel if available, etc.

Next, at 530, the telephony network processor 24 on the user device 20requests the user device database 22 to provide any pre-provisionedinformation about emergency broadcast information associated with userdevice 20. Then, in response at 540, the user device database 22 returnsany one or more of the following non-exhaustive, non-limiting, types ofemergency alerting information to the telephony processor 24 on the userdevice 20: available broadcast technologies (e.g., Cell Broadcast, MBMS,DVB-H, MediaFLO), broadcast technologies supported by the device 20 orassociated emergency broadcast channels for each available broadcasttechnology.

Finally, at 550, using the information from the user device 20 retrievedat step 540, the telephony processor 24 interacts with the userinterface 28 of the user device 20 to inform the end user that anemergency alert is being broadcast. User interface 28 is not limited todisplay of information, however. Any known output device for a userdevice 20 may be utilized, whether visual, auditory and/or mechanical inoperation. For example, special alert tones may be activated and specialdisplay graphics, symbols, text, etc. may be portrayed on a display ofthe user device 20 that inform the user that an emergency broadcast isbeing sent and to which channel or channels the user should tune for theemergency broadcast. In a non-limiting embodiment, a programmed soft key(or hardware control) may be provided for the end user to access theemergency broadcast immediately, or as mentioned, optionally, the userdevice 20 may automatically tune to the emergency broadcast.

FIG. 3 is an exemplary, non-limiting flow diagram of a process, whichmay proceed independent of and concurrently with the process of FIG. 2,for delivering emergency information via any of the existing broadcasttechnologies supported by a broadcast processor 26 of the user device20. In FIG. 3, at 300, the broadcast network(s) 60 receive an emergencyalert from the emergency alert network 50, such as the EAS. Then, at310, the broadcast network starts broadcasting the received emergencyalert. Then, at 320, whether activation occurs automatically oroptionally at the behest of a user that has been notified of the alert(e.g., via the process of FIG. 2), the associated emergency broadcastchannel of the user device 20 is activated, the broadcast processor 26receives the broadcasted emergency alert data and displays the emergencyalert via the user interface 28 of the user device 20.

EAS Alerting by Automatically Adjusting User Settings on a Handset

Some portable devices may provide a user with the ability to turn offthe emergency alert monitoring because of the reasons mentioned above.For example, continuous monitoring of the control channel for emergencybroadcasts can cause a drain on battery life. Moreover, there are somemessages that are sent on the emergency broadcast system that users maynot want to receive. Consequently, a number of users choose to changethe settings on the portable device to disable monitoring of emergencybroadcasts.

Such disabling of emergency broadcast monitoring is problematic incertain emergency situations such as a terrorist attack, a chemicalspill, etc. In such instances, portable devices that have the emergencybroadcast monitoring turned off will not receive the message.Consequently, the users of such portable devices may not be aware of theemergency situation. In order to overcome that issue, an indicator suchas a flag is set in the system information sent to the phone to causethe phone to turn on broadcast channel monitoring regardless of userselected phone settings. The flag could be a bit, a byte, a set of bits,etc. that represent the state of the EAS broadcast system. For example,a bit could be set to indicate that EAS broadcast is on or not set toindicate that EAS broadcast is off.

In one embodiment, the flag is part of the control channel informationdirected specifically to the phone. In another embodiment, the flag isset in channel information that is simultaneously monitored by allphones in a particular cell.

Common channels can be accessed both by idle mode and dedicated modemobiles. Common channels are used by idle mode mobiles to exchange thesignaling information required to change to dedicated mode. Mobilesalready in dedicated mode monitor the surrounding base stations forhandover and other information. The common channels include:

-   -   Broadcast Control Channel (BCCH): Continuously broadcasts, on        the downlink, information including base station identity,        frequency allocations, and frequency-hopping sequences.    -   Frequency Correction Channel (FCCH) and Synchronization Channel        (SCH): Used to synchronize the portable device to the time slot        structure of a cell. Every cell in a GSM network broadcasts one        FCCH and one SCH, which are on time slot 0.    -   Random Access Channel (RACH): Slotted Aloha channel used by the        portable device to request access to the network.    -   Paging Channel (PCH): Used to alert the portable device of an        incoming call.    -   Access Grant Channel (AGCH): Used to allocate an SDCCH to a        portable device for signaling (in order to obtain a dedicated        channel), following a request on the RACH.

The flag could be set on any one of the above communication channelsbetween a portable device and a base station. Moreover, the flag couldbe set on a different control channel than those outlined above asvarious communication standards evolved and new standards are defined.More specifically, a flag indicating that EAS cell broadcast is on oroff is sent in the system information message. When the flag is set toindicate EAS cell broadcast is on, The portable device can thenimmediately change the portable device settings to turn on the cellbroadcast feature, overriding previous user settings.

The portable device could be programmed to revert to the previous usersettings after a timeout period. Alternatively, the portable devicecould change the settings back to the user settings when the flag ischanged in the system information to EAS cell broadcast is off.

Exemplary Non-Limiting Network and Operating Environments

The following description sets forth some exemplary telephony radionetworks and non-limiting operating environments for the EAS alertreporting services of the present invention. The below-describedoperating environments should be considered non-exhaustive, however, andthus the below-described network architectures merely show how theservices of the present invention may be incorporated into existingnetwork structures and architectures. One can appreciate, however, thatthe invention may be incorporated into now existing or futurealternative architectures for communication networks as well.

The global system for mobile communication (“GSM”) is one of the mostwidely utilized wireless access systems in today's fast growingcommunication systems. GSM provides circuit-switched data services tosubscribers, such as mobile telephone or computer users. General PacketRadio Service (“GPRS”), which is an extension to GSM technology,introduces packet switching to GSM networks. GPRS uses a packet-basedwireless communication technology to transfer high and low speed dataand signaling in an efficient manner. GPRS optimizes the use of networkand radio resources, thus enabling the cost effective and efficient useof GSM network resources for packet mode applications.

As one of ordinary skill in the art can appreciate, the exemplaryGSM/GPRS environment and services described herein can also be extendedto 3G services, such as Universal Mobile Telephone System (“UMTS”),Frequency Division Duplexing (“FDD”) and Time Division Duplexing(“TDD”), High Speed Packet Data Access (“HSPDA”), cdma2000 1x EvolutionData Optimized (“EVDO”), Code Division Multiple Access-2000 (“cdma20003x”), Time Division Synchronous Code Division Multiple Access(“TD-SCDMA”), Wideband Code Division Multiple Access (“WCDMA”), EnhancedData GSM Environment (“EDGE”), International MobileTelecommunications-2000 (“IMT-2000”), Digital Enhanced CordlessTelecommunications (“DECT”), etc., as well as to other network servicesthat shall become available in time. In this regard, the techniques ofthe invention may be applied independently of the method of datatransport, and does not depend on any particular network architecture,or underlying protocols.

FIG. 5A depicts an overall block diagram of an exemplary packet-basedmobile cellular network environment, such as a GPRS network, in whichthe invention may be practiced. In such an environment, there are aplurality of Base Station Subsystems (“BSS”) 200 (only one is shown),each of which comprises a Base Station Controller (“BSC”) 202 serving aplurality of Base Transceiver Stations (“BTS”) such as BTSs 204, 206,and 208. BTSs 204, 206, 208, etc. are the access points where users ofpacket-based mobile devices become connected to the wireless network. Inexemplary fashion, the packet traffic originating from user devices istransported over the air interface to a BTS 208, and from the BTS 208 tothe BSC 202. Base station subsystems, such as BSS 200, are a part ofinternal frame relay network 210 that may include Service GPRS SupportNodes (“SGSN”) such as SGSN 212 and 214. Each SGSN is in turn connectedto an internal packet network 220 through which a SGSN 212, 214, etc.can route data packets to and from a plurality of gateway GPRS supportnodes (GGSN) 222, 224, 226, etc. As illustrated, SGSN 214 and GGSNs 222,224, and 226 are part of internal packet network 220. Gateway GPRSserving nodes 222, 224 and 226 mainly provide an interface to externalInternet Protocol (“IP”) networks such as Public Land Mobile Network(“PLMN”) 250, corporate intranets 240, or Fixed-End System (“FES”) orthe public Internet 230. As illustrated, subscriber corporate network240 may be connected to GGSN 224 via firewall 232; and PLMN 250 isconnected to GGSN 224 via boarder gateway router 234. The RemoteAuthentication Dial-In User Service (“RADIUS”) server 242 may be usedfor caller authentication when a user of a mobile cellular device callscorporate network 240.

Generally, there can be four different cell sizes in a GSMnetwork—macro, micro, pico and umbrella cells. The coverage area of eachcell is different in different environments. Macro cells can be regardedas cells where the base station antenna is installed in a mast or abuilding above average roof top level. Micro cells are cells whoseantenna height is under average roof top level; they are typically usedin urban areas. Pico cells are small cells having a diameter is a fewdozen meters; they are mainly used indoors. On the other hand, umbrellacells are used to cover shadowed regions of smaller cells and fill ingaps in coverage between those cells.

FIG. 5B illustrates the architecture of a typical GPRS network assegmented into four groups: users 250, radio access network 260, corenetwork 270, and interconnect network 280. Users 250 comprise aplurality of end users (though only mobile subscriber 255 is shown inFIG. 5B). Radio access network 260 comprises a plurality of base stationsubsystems such as BSSs 262, which include BTSs 264 and BSCs 266. Corenetwork 270 comprises a host of various network elements. As illustratedhere, core network 270 may comprise Mobile Switching Center (“MSC”) 271,Service Control Point (“SCP”) 272, gateway MSC 273, SGSN 276, HomeLocation Register (“HLR”) 274, Authentication Center (“AuC”) 275, DomainName Server (“DNS”) 277, and GGSN 278. Interconnect network 280 alsocomprises a host of various networks and other network elements. Asillustrated in FIG. 5B, interconnect network 280 comprises PublicSwitched Telephone Network (“PSTN”) 282, Fixed-End System (“FES”) orInternet 284, firewall 288, and Corporate Network 289.

A mobile switching center can be connected to a large number of basestation controllers. At MSC 271, for instance, depending on the type oftraffic, the traffic may be separated in that voice may be sent toPublic Switched Telephone Network (“PSTN”) 282 through Gateway MSC(“GMSC”) 273, and/or data may be sent to SGSN 276, which then sends thedata traffic to GGSN 278 for further forwarding.

When MSC 271 receives call traffic, for example, from BSC 266, it sendsa query to a database hosted by SCP 272. The SCP 272 processes therequest and issues a response to MSC 271 so that it may continue callprocessing as appropriate.

The HLR 274 is a centralized database for users to register to the GPRSnetwork. HLR 274 stores static information about the subscribers such asthe International Mobile Subscriber Identity (“IMSI”), subscribedservices, and a key for authenticating the subscriber. HLR 274 alsostores dynamic subscriber information such as the current location ofthe mobile subscriber. Associated with HLR 274 is AuC 275. AuC 275 is adatabase that contains the algorithms for authenticating subscribers andincludes the associated keys for encryption to safeguard the user inputfor authentication.

In the following, depending on context, the term “mobile subscriber”sometimes refers either to the end user and sometimes to the actualportable device used by an end user of the mobile cellular service. Whena mobile subscriber turns on his or her mobile device, the mobile devicegoes through an attach process by which the mobile device attaches to anSGSN of the GPRS network. In FIG. 5B, when mobile subscriber 255initiates the attach process by turning on the network capabilities ofthe mobile device, an attach request is sent by mobile subscriber 255 toSGSN 276. The SGSN 276 queries another SGSN, to which mobile subscriber255 was attached before, for the identity of mobile subscriber 255. Uponreceiving the identity of mobile subscriber 255 from the other SGSN,SGSN 276 requests more information from mobile subscriber 255. Thisinformation is used to authenticate mobile subscriber 255 to SGSN 276 byHLR 274. Once verified, SGSN 276 sends a location update to HLR 274indicating the change of location to a new SGSN, in this case SGSN 276.HLR 274 notifies the old SGSN, to which mobile subscriber 255 wasattached before, to cancel the location process for mobile subscriber255. HLR 274 then notifies SGSN 276 that the location update has beenperformed. At this time, SGSN 276 sends an Attach Accept message tomobile subscriber 255, which in turn sends an Attach Complete message toSGSN 276.

After attaching itself with the network, mobile subscriber 255 then goesthrough the authentication process. In the authentication process, SGSN276 sends the authentication information to HLR 274, which sendsinformation back to SGSN 276 based on the user profile that was part ofthe user's initial setup. The SGSN 276 then sends a request forauthentication and ciphering to mobile subscriber 255. The mobilesubscriber 255 uses an algorithm to send the user identification (ID)and password to SGSN 276. The SGSN 276 uses the same algorithm andcompares the result. If a match occurs, SGSN 276 authenticates mobilesubscriber 255.

Next, the mobile subscriber 255 establishes a user session with thedestination network, corporate network 289, by going through a PacketData Protocol (“PDP”) activation process. Briefly, in the process,mobile subscriber 255 requests access to the Access Point Name (“APN”),for example, UPS.com (e.g., which can be corporate network 279 in FIG.3) and SGSN 276 receives the activation request from mobile subscriber255. SGSN 276 then initiates a Domain Name Service (“DNS”) query tolearn which GGSN node has access to the UPS.com APN. The DNS query issent to the DNS server within the core network 270, such as DNS 277,which is provisioned to map to one or more GGSN nodes in the corenetwork 270. Based on the APN, the mapped GGSN 278 can access therequested corporate network 279. The SGSN 276 then sends to GGSN 278 aCreate Packet Data Protocol (“PDP”) Context Request message thatcontains necessary information. The GGSN 278 sends a Create PDP ContextResponse message to SGSN 276, which then sends an Activate PDP ContextAccept message to mobile subscriber 255.

Once activated, data packets of the call made by mobile subscriber 255can then go through radio access network 260, core network 270, andinterconnect network 280, in particular fixed-end system or Internet 284and firewall 288, to reach corporate network 289.

Thus, network elements that may implicate the functionality of the EASalert reporting in accordance with the invention may include but are notlimited to Gateway GPRS Support Node tables, Fixed End System routertables, firewall systems, VPN tunnels, and any number of other networkelements as required by the particular digital network.

FIG. 5C shows another exemplary block diagram view of a GSM/GPRS/IPmultimedia network architecture 100 in which the EAS alerting andreporting of the present invention may be incorporated. As illustrated,architecture 100 of FIG. 5C includes a GSM core network 101, a GPRSnetwork 130 and an IP multimedia network 138. The GSM core network 101includes a Mobile Station (MS) 102, at least one Base TransceiverStation (BTS) 104 and a Base Station Controller (BSC) 106. The MS 102 isphysical equipment or Mobile Equipment (ME), such as a mobile phone or alaptop computer that is used by mobile subscribers, with a Subscriberidentity Module (SIM). The SIM includes an International MobileSubscriber Identity (IMSI), which is a unique identifier of asubscriber. The BTS 104 is physical equipment, such as a radio tower,that enables a radio interface to communicate with the MS. Each BTS mayserve more than one MS. The BSC 106 manages radio resources, includingthe BTS. The BSC may be connected to several BTSs. The BSC and BTScomponents, in combination, are generally referred to as a base station(BSS) or radio access network (RAN) 103.

The GSM core network 101 also includes a Mobile Switching Center (MSC)108, a Gateway Mobile Switching Center (GMSC) 110, a Home LocationRegister (HLR) 112, Visitor Location Register (VLR) 114, anAuthentication Center (AuC) 118, and an Equipment Identity Register(EIR) 116. The MSC 108 performs a switching function for the network.The MSC also performs other functions, such as registration,authentication, location updating, handovers, and call routing. The GMSC110 provides a gateway between the GSM network and other networks, suchas an Integrated Services Digital Network (ISDN) or Public SwitchedTelephone Networks (PSTNs) 120. In other words, the GMSC 110 providesinterworking functionality with external networks.

The HLR 112 is a database that contains administrative informationregarding each subscriber registered in a corresponding GSM network. TheHLR 112 also contains the current location of each MS. The VLR 114 is adatabase that contains selected administrative information from the HLR112. The VLR contains information necessary for call control andprovision of subscribed services for each MS currently located in ageographical area controlled by the VLR. The HLR 112 and the VLR 114,together with the MSC 108, provide the call routing and roamingcapabilities of GSM. The AuC 116 provides the parameters needed forauthentication and encryption functions. Such parameters allowverification of a subscriber's identity. The EIR 118 storessecurity-sensitive information about the mobile equipment.

A Short Message Service Center (SMSC) 109 allows one-to-one ShortMessage Service (SMS) messages to be sent to/from the MS 102. A PushProxy Gateway (PPG) 111 is used to “push” (i.e., send without asynchronous request) content to the MS 102. The PPG 111 acts as a proxybetween wired and wireless networks to facilitate pushing of data to theMS 102. A Short Message Peer to Peer (SMPP) protocol router 113 isprovided to convert SMS-based SMPP messages to cell broadcast messages.SMPP is a protocol for exchanging SMS messages between SMS peer entitiessuch as short message service centers. It is often used to allow thirdparties, e.g., content suppliers such as news organizations, to submitbulk messages.

To gain access to GSM services, such as speech, data, and short messageservice (SMS), the MS first registers with the network to indicate itscurrent location by performing a location update and IMSI attachprocedure. The MS 102 sends a location update including its currentlocation information to the MSC/VLR, via the BTS 104 and the BSC 106.The location information is then sent to the MS's HLR. The HLR isupdated with the location information received from the MSC/VLR. Thelocation update also is performed when the MS moves to a new locationarea. Typically, the location update is periodically performed to updatethe database as location updating events occur.

The GPRS network 130 is logically implemented on the GSM core networkarchitecture by introducing two packet-switching network nodes, aserving GPRS support node (SGSN) 132, a cell broadcast and a GatewayGPRS support node (GGSN) 134. The SGSN 132 is at the same hierarchicallevel as the MSC 108 in the GSM network. The SGSN controls theconnection between the GPRS network and the MS 102. The SGSN also keepstrack of individual MS's locations and security functions and accesscontrols.

A Cell Broadcast Center (CBC) 133 communicates cell broadcast messagesthat are typically delivered to multiple users in a specified area. CellBroadcast is one-to-many geographically focused service. It enablesmessages to be communicated to multiple mobile phone customers who arelocated within a given part of its network coverage area at the time themessage is broadcast.

The GGSN 134 provides a gateway between the GPRS network and a publicpacket network (PDN) or other IP networks 136. That is, the GGSNprovides interworking functionality with external networks, and sets upa logical link to the MS through the SGSN. When packet-switched dataleaves the GPRS network, it is transferred to an external TCP-IP network136, such as an X.25 network or the Internet. In order to access GPRSservices, the MS first attaches itself to the GPRS network by performingan attach procedure. The MS then activates a packet data protocol (PDP)context, thus activating a packet communication session between the MS,the SGSN, and the GGSN.

In a GSM/GPRS network, GPRS services and GSM services can be used inparallel. The MS can operate in one three classes: class A, class B, andclass C. A class A MS can attach to the network for both GPRS servicesand GSM services simultaneously. A class A MS also supports simultaneousoperation of GPRS services and GSM services. For example, class Amobiles can receive GSM voice/data/SMS calls and GPRS data calls at thesame time.

A class B MS can attach to the network for both GPRS services and GSMservices simultaneously. However, a class B MS does not supportsimultaneous operation of the GPRS services and GSM services. That is, aclass B MS can only use one of the two services at a given time.

A class C MS can attach for only one of the GPRS services and GSMservices at a time. Simultaneous attachment and operation of GPRSservices and GSM services is not possible with a class C MS.

A GPRS network 130 can be designed to operate in three network operationmodes (NOM1, NOM2 and NOM3). A network operation mode of a GPRS networkis indicated by a parameter in system information messages transmittedwithin a cell. The system information messages dictates a MS where tolisten for paging messages and how signal towards the network. Thenetwork operation mode represents the capabilities of the GPRS network.In a NOM1 network, a MS can receive pages from a circuit switched domain(voice call) when engaged in a data call. The MS can suspend the datacall or take both simultaneously, depending on the ability of the MS. Ina NOM2 network, a MS may not receive pages from a circuit switcheddomain when engaged in a data call, since the MS is receiving data andis not listening to a paging channel In a NOM3 network, a MS can monitorpages for a circuit switched network while received data and vice versa.

The IP multimedia network 138 was introduced with 3GPP Release 5, andincludes an IP multimedia subsystem (IMS) 140 to provide rich multimediaservices to end users. A representative set of the network entitieswithin the IMS 140 are a call/session control function (CSCF), a mediagateway control function (MGCF) 146, a media gateway (MGW) 148, and amaster subscriber database, called a home subscriber server (HSS) 150.The HSS 150 may be common to the GSM network 101, the GPRS network 130as well as the IP multimedia network 138.

The IP multimedia system 140 is built around the call/session controlfunction, of which there are three types: an interrogating CSCF (I-CSCF)143, a proxy CSCF (P-CSCF) 142, and a serving CSCF (S-CSCF) 144. TheP-CSCF 142 is the MS's first point of contact with the IMS 140. TheP-CSCF 142 forwards session initiation protocol (SIP) messages receivedfrom the MS to an SIP server in a home network (and vice versa) of theMS. The P-CSCF 142 may also modify an outgoing request according to aset of rules defined by the network operator (for example, addressanalysis and potential modification).

The I-CSCF 143, forms an entrance to a home network and hides the innertopology of the home network from other networks and providesflexibility for selecting an S-CSCF. The I-CSCF 143 may contact asubscriber location function (SLF) 145 to determine which HSS 150 to usefor the particular subscriber, if multiple HSS's 150 are present. TheS-CSCF 144 performs the session control services for the MS 102. Thisincludes routing originating sessions to external networks and routingterminating sessions to visited networks. The S-CSCF 144 also decideswhether an application server (AS) 152 is required to receiveinformation on an incoming SIP session request to ensure appropriateservice handling. This decision is based on information received fromthe HSS 150 (or other sources, such as an application server 152). TheAS 152 also communicates to a location server 156 (e.g., a GatewayMobile Location Center (GMLC)) that provides a position (e.g.,latitude/longitude coordinates) of the MS 102.

The HSS 150 contains a subscriber profile and keeps track of which corenetwork node is currently handling the subscriber. It also supportssubscriber authentication and authorization functions (AAA). In networkswith more than one HSS 150, a subscriber location function providesinformation on the HSS 150 that contains the profile of a givensubscriber.

The MGCF 146 provides interworking functionality between SIP sessioncontrol signaling from the IMS 140 and ISUP/BICC call control signalingfrom the external GSTN networks (not shown). It also controls the mediagateway (MGW) 148 that provides user-plane interworking functionality(e.g., converting between AMR- and PCM-coded voice). The MGW 148 alsocommunicates with other IP multimedia networks 154.

Push to Talk over Cellular (PoC) capable mobile phones register with thewireless network when the phones are in a predefined area (e.g., jobsite, etc.). When the mobile phones leave the area, they register withthe network in their new location as being outside the predefined area.This registration, however, does not indicate the actual physicallocation of the mobile phones outside the pre-defined area.

While the present invention has been described in connection with thepreferred embodiments of the various Figures, it is to be understoodthat other similar embodiments may be used or modifications andadditions may be made to the described embodiment for performing thesame function of the present invention without deviating therefrom. Forexample, one skilled in the art will recognize that the presentinvention as described in the present application may apply to anyenvironment, whether wired or wireless, and may be applied to any numberof such devices connected via a communications network and interactingacross the network. Therefore, the present invention should not belimited to any single embodiment, but rather should be construed inbreadth and scope in accordance with the appended claims.

What is claimed is:
 1. A method comprising: receiving, at a device,broadcast information, wherein the broadcast information comprisesinformation about available broadcast technologies and information aboutbroadcast channels associated with each of the available broadcasttechnologies; storing, by the device, the broadcast information;receiving, at the device, an instruction not to engage in broadcastchannel monitoring; monitoring, by the device, a control channel of thedevice; receiving, at the device, via the control channel, an indicationthat an alert is being broadcast; retrieving, responsive to the request,the stored broadcast information; overriding the instruction, whereinbroadcast monitoring is enabled as a result of the overriding;responsive to the overriding, tuning, based on the retrieved broadcastinformation, to a broadcast channel of the broadcast channels associatedwith the available broadcast technologies; receiving, via the tunedbroadcast channel, an emergency alert broadcast from an emergency alertnetwork; and responsive to receiving the emergency alert broadcast,after a predefined period of time has expired on the device, resettingthe instruction not to engage in broadcast monitoring.
 2. The method ofclaim 1, wherein the device comprises a mobile phone.
 3. The method ofclaim 1, further comprising receiving an indicator bit via the controlchannel.
 4. The method of claim 3, wherein the indicator bit indicatesthe emergency alert broadcast is no longer being broadcast.
 5. Themethod of claim 1, further comprising rendering, on the device, anindication of the emergency alert broadcast.
 6. The method of claim 5,wherein the rendering comprises at least one of a visual rendering, anauditory rendering, or a mechanical rendering.
 7. The method of claim 1,wherein the control channel comprises at least one of a frequencycorrection channel, a synchronization channel, a random access channel,a paging channel, or an access grant channel.
 8. A device comprising: aprocessor; and memory coupled to the processor, the memory comprisingexecutable instructions that when executed by the processor cause theprocessor to effectuate operations comprising: receiving, at the device,broadcast information, wherein the broadcast information comprisesinformation about available broadcast technologies and information aboutbroadcast channels associated with each of the available broadcasttechnologies; storing, by the device, the broadcast information;receiving, at the device, an instruction not to engage in broadcastchannel monitoring; monitoring, by the device, a control channel of thedevice; receiving, at the device, via the control channel, an indicationthat an alert is being broadcast; retrieving, responsive to the request,the stored broadcast information; overriding the instruction, whereinbroadcast monitoring is enabled as a result of the overriding;responsive to the overriding, tuning, based on the retrieved broadcastinformation, to a broadcast channel of the broadcast channels associatedwith the available broadcast technologies; receiving, via the tunedbroadcast channel, an emergency alert broadcast from an emergency alertnetwork; and responsive to receiving the emergency alert broadcast,after a predefined period of time has expired on the device, resettingthe instruction not to engage in broadcast monitoring.
 9. The device ofclaim 8, wherein the device comprises a mobile phone.
 10. The device ofclaim 8, the operations further comprising receiving an indicator bitvia the control channel.
 11. The device of claim 10, wherein theindicator bit indicates the emergency alert broadcast is no longer beingbroadcast.
 12. The device of claim 8, the operations further comprisingrendering, on the device, an indication of the emergency alertbroadcast.
 13. The device of claim 12, wherein the rendering comprisesat least one of a visual rendering, an auditory rendering, or amechanical rendering.
 14. The device of claim 8, wherein the controlchannel comprises at least one of a frequency correction channel, asynchronization channel, a random access channel, a paging channel, oran access grant channel.
 15. A storage device having stored thereoncomputer executable instructions when executed by a processor cause theprocessor to effectuate operations comprising: receiving, at acommunications device, broadcast information, wherein the broadcastinformation comprises information about available broadcast technologiesand information about broadcast channels associated with each of theavailable broadcast technologies; storing, by the communications device,the broadcast information; receiving, at the communications device, aninstruction not to engage in broadcast channel monitoring; monitoring,by the communications device, a control channel of the communicationsdevice; receiving, at the communications device, via the controlchannel, an indication that an alert is being broadcast; retrieving,responsive to the request, the stored broadcast information; overridingthe instruction, wherein broadcast monitoring is enabled as a result ofthe overriding; responsive to the overriding, tuning, based on theretrieved broadcast information, to a broadcast channel of the broadcastchannels associated with the available broadcast technologies;receiving, via the tuned broadcast channel, an emergency alert broadcastfrom an emergency alert network; and responsive to receiving theemergency alert broadcast, after a predefined period of time has expiredon the communications device, resetting the instruction not to engage inbroadcast monitoring.
 16. The storage device of claim 15, wherein thecommunications device comprises a mobile phone.
 17. The storage deviceof claim 15, further comprising receiving an indicator bit via thecontrol channel.
 18. The storage device of claim 17, wherein theindicator bit indicates the emergency alert broadcast is no longer beingbroadcast.
 19. The storage device of claim 15, further comprisingrendering, on the communications device, an indication of the emergencyalert broadcast.
 20. The storage device of claim 15, wherein the controlchannel comprises at least one of a frequency correction channel, asynchronization channel, a random access channel, a paging channel, oran access grant channel.